In vitro recalcification of the demineralized shell-repair membrane of the snail,Helix pomatia L.

Summary The role of the amoebocytes in the calcification process of the shell-repair membrane of the snail, Helix pomatia, was investigated in vitro. The shell-repair membranes were demineralized with 0.5 M EDTA at pH 7.4. For the recalcification of the demineralized membranes two substrates were chosen: (i) Tris-buffered Helix pomatia-saline, pH 7.4, and (ii) Helix pomatia-saline supplemented with 5 mM CaCl₂ and 5 mM NaHCO₃. The membranes were incubated in 2 ml substrate at 37° C and examined after 2 h, 24 h, and 3, 5 and 7 days. Calcium deposition and crystal formation were observed within the membrane incubated in the salt-supplemented substrate. The control membranes were either heat-inactivated or deprived of lipids. No calcium precipitation was observed in control membranes. The experiments show that the recalcification of the shell-repair membrane is under strict cellular control and that the granules released from the amoebocytes serve as sites for calcium deposition. The role of phospholipids in the calcification process is discussed.